We sometimes are called upon to "rescue" a failed project. While there are many reasons which can lead to a project needing to be rescued, these three are frequent offenders. You know the sad thing? They are all preventable.
In the three cases I will discuss, project failure isn't some abstract concept known only after the fact. You see it coming, with a sense of impending doom as your project is caught in a landslide, hurtling toward a cliff. That is the common theme of these problems; you come to realize you are in trouble, but it is too late to do much of anything about it but watch.
Another common theme is how pitfalls unfold. Your project looks ok, looks ok, looks a little behind, oh no - big trouble!
1. Understimating the complexity and scope
This pitfall unfolds as your project progresses, and you continue to find little things that are needed, but were not planned. Most are minor gaps in the scope you defined, but as they occur and accumulate you get further and further behind.
At the conceptual stage, and even sometimes at the approval stage, the big outlines of the project are known and understood. But the details haven't been established, and missing a small but critical detail can derail any project.
Before the project is approved, if possible, and at the least immediately after the project is approved, there should be a diligent scope-defining exercise. This should drill down to individual tasks and needs, and so far as possible, into the construction sequence.
Without this diligence, all the little details will get done. But they will get done when you realize the need which may be too late to keep your project on track.
With most of the little details defined up front, you can prepare for them, sequence the work, track them, and insure they don't slow down your project. And you can focus on the few that you missed.